Burglar-alarm



(No Moden) l J. ISRAEL.

BURGLAR ALARM.

110.386,131. Patented July 1'7, 1888.

l 8 wlNEssEs lNvENToR.

' 1 .fozn Ircwl UNITED STATES PATENT OFFICE.

JOHN ISRAEL, OF ST. LOUIS, MISSOURI.

BURGLAR-ALARIVI.

SPECIFICATION forming part of Letters Patent No. 386,131, dated Juiy 17, 1888.

Application tiled February 2,1888. Serial No. 262,792.

T0 all whom, it 77mg/ concern:

Be it known that I, Jol-1N IsRAEL, of St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Burglar-Alarms, of which the following is a speciication.

My improvements relate to detonating burglar-alarms of the class shown in my United States Patents Nos. 193,002 and 224,017.

The object of my present invention is toimprove such detonating burglar-alarms by providing means for causing two explosions, one following another,with any desired interval of time between them.

It is well known that frequently a single explosion will not fully awaken personsinstantly, and if they are awakened by it they are so much bewildered as not to be able to understand its location or significance; but a single explosion will usually put the mind upon the qui vire, and a second explosion following in a few seconds` will fully serve to convey to the mind ot' a person suddenly awakened its full significance. A second explosion also will be sure to overcome the plottings of a criminal attempting burglary if the first one would not. It is therefore desirable in detonating burglaralarms to provide for a second explosion to follow within a. few seconds after the tirst. Accordingly, in connection with such a detonating burglar alarm-for example, as shown in my United States Patent No. l93,002,where provision is made for exploding a fulminate- I provide an additional receptacle for another fulminate or explosive bomb having a fuse to be ignited by the first discharge, which fuse will presently ignite the second explosive.

In the accompanying drawings, Figure lis a longitudinal vertical section, partly in eleva- (No model.)

tion,of my tiring mechanism applied to a door" jamb,X,in position to be fired upon the opening ofthe door Y, as indicated in dotted lines. Fig. 2 is a longitudinal section of the firingplunger and its spring detached.

Referring to the letters upon the drawings, A indicates a hollow cylinder provided with a springplunger, B, a fulminate-slot, C, a screw-standard, D, and a screwcap, E, all substantially as shown in my said patent, No. 193,002. The end of the cylinder, near the fulminate-slot, is preferably screw-threaded at F to receivea hollow cylindrical extension,G, provided with a female screw-thread,as shown, and with an opening, H, preferably of rectangular form,for the insertion of awrencll. The fulminate in the slot C being exploded,the gas will pass through the small opening K into the interior of the extension G and ignite the fuse L of the bomb M, which will presently explode and the gas will pass out of the opening I-I.

\Vhat I claim as my improvements, and desire to secure by Letters Patent of the United States, is-

In a detonating burglar alarm, the combination ofthe hollow firing-cylinder A, screwt-hreaded at F, and the hollow cylindrical extension G for carrying a second explosive, screw-threaded and provided with the openings K and L, whereby the firing-cylinder can be elongated and caused to fire two explosives at will, substantially as set forth.

In testimony whereof I have hereunto subscribed my name.

JOHN ISRAEL.

Vitnesses:

C. I. ELWELL,

MARCUS S. HOPKINS. 

